How to calculate the effective accumulated temperature? How to calculate accumulated temperatureHow

The effective accumulated temperature refers to the daily accumulation of temperature that can promote the development of gonads, that is, the daily accumulation of the daily average temperature values above the biological zero of various organisms. The unit of effective accumulated temperature is expressed as " ?days".

It is understood that the effective accumulated temperature of the wrinkle abalone in Dalian is 500 1000 ?days (biological zero was not measured, using Japanese, the induction rate and spawning of abalone increased with the increase of effective accumulated temperature; When more than 1100 ?The induced sperm and oviposition rates of males and females were close to 100% (Liu et al., 1986).

And the Japanese wrinkled abalone male to reach 1000 ?days, only 100% of individuals can be ejaculation; Females should reach 1500 ?days, only 100% of individuals spawn (Kikuchi & Float, 1974).

This may be due to the large difference in water temperature between the two sea areas, the water temperature in the Dalian sea area in winter and spring is low and long, and the effective accumulated temperature value in the sea area of Japan cannot reach the effective accumulated temperature value.

Each plant has its lower limit temperature for growth. When the temperature is higher than the lower limit temperature, it can grow and develop. This higher temperature, which plays an effective role in the growth and development of plants, is called the effective accumulated temperature. The sum of the effective temperatures of the plant over the entire growth period.

k = n（t - c）

k: the total amount of heat required by the plant to complete a certain stage of development, expressed by "day" n: the development period, that is, the number of days required to complete a certain stage of development t: the average temperature during development.

c: Developmental threshold temperature of the plant.

1. When calculating the accumulated temperature, it is divided into two types: active accumulated temperature and effective accumulated temperature. The so-called active accumulated temperature is the accumulation of the active temperature that is higher than the temperature at the beginning of crop growth.

2. If rice requires a daily average temperature of more than 10 to grow, then 10 is the starting temperature of rice growth, and the daily average temperature higher than 10 is called the active temperature, and the sum of the daily active temperature in the growing season is the active accumulated temperature.

3. If the average temperature of a certain day is: , add the activity temperature of four of the days: day, that is, the active accumulated temperature of the five days, of which less than 10 or just 10 is not added.

Subtract the starting point from the average temperature above 10. Temperature 10 is the effective temperature. The sum of the effective temperatures is the effective accumulated temperature.

4. If the average temperature of the above five days is calculated, the effective accumulated temperature is calculated as: days. The effective accumulated temperature is the temperature that has a positive impact on the growth and development of crops, which reflects that the relationship between rice growth and development and temperature is closer to the actual situation than the active accumulated temperature, so the effective accumulated temperature is generally used more in production.

The main meaning of the effective accumulated temperature rule is that in the process of growth and development, plants must take a certain amount of heat from the outside world to complete their development at a certain stage, and the total heat required by plants at each stage of development is a constant.

The relationship between temperature and biological development is mainly reflected in the influence of temperature on the development rate of plants and ectotherms (especially insects), that is, it is reflected in the law of effective accumulated temperature.

The effective accumulated temperature law was originally summarized in the study of plant development, and its main implication is that plants must take a certain amount of heat from the environment in the process of growth and development to complete a certain stage of development, and the total heat required by each stage of plant development is a constant.

Limitations of the effective accumulated temperature rule.

1. At present, the estimation of effective accumulated temperature is still based on the basic formula of effective accumulated temperature under the premise that the temperature of insects in the suitable temperature zone is proportional to the development rate.

2. Some insects have the possibility of developing a constant temperature zone on the relationship curve between temperature and development rate (within the optimal temperature range). This is also a factor that brings about bias.

3. Some materials with effective accumulated temperature are obtained under indoor constant temperature feeding conditions, but the development of insects in nature is in the process of changing temperature, and the development of insects is often faster than the corresponding constant temperature under a certain change temperature. In addition, the average daily temperature in meteorology does not fully reflect the actual temperature difference, and it is not exactly the same as the microclimate environment in which insects actually live.

The main meaning of the effective accumulated temperature law is that each insect must take a certain amount of heat from the outside world to complete its development at a certain stage in the process of growth and development, and the total heat required by each stage of development of insects is a constant. It can be expressed by the following formula:

k = n t where n is the time required in the growth phase, which is called the development period. t is the average temperature during the growth period. k is a constant, i.e., the total accumulated temperature.

Since the development of insects does not start at 0, but only at a specific temperature above 0, this temperature is called the starting temperature c (i.e., the lowest effective temperature). Then the above formula can be modified as: k= n(t-c) i.e., t=c+k n=c+kv, where the rate of development (v) is the reciprocal of time (n).

Effects of temperature on biological development.

The law of temperature on the development of organisms - the law of effective accumulated temperature.

It refers to the process of biological growth and development, a certain amount of heat must be taken from the environment to complete a certain stage of development, and the total amount of calories required for each stage is a constant, which can be expressed by a formula.

k = n（t–t0）

where: k - the effective accumulated temperature required by the organism, which is a constant;

t - the average temperature of the local area for that period;

t0 - the minimum critical temperature (temperature of the zero degree or the beginning of development) required for the growth activity of the organism

n – the time elapsed by the growth and development of the organism, d.

Calculation method of net effective accumulated temperature:The sum of the effective temperatures during the growth period is called the effective accumulated temperature (A-value). It does not contain the temperature and sail degree below the n value, so it can better characterize the heat k required for the reproduction of biological organisms, and is mostly used in the calculation of the development rate t of biological organic traces

1. K: The total amount of calories required by plants to complete a certain stage of development, expressed as "day".

2. n: the development period, that is, the number of days required to complete a certain stage of development.

3. t: the average temperature during development.

4. C: The developmental threshold temperature of the plant. The average temperature steadily decreases to below 1o as winter begins, and the phenological average temperature stabilizes from below 10 Climatologists combine phenological phenomena with agricultural production to divide the seasons.

Data analysis. Steady rise to 22 as the start of summer; When the average temperature rises steadily from below 10 to above 10, it is the beginning of spring; When it steadily drops from above 22 to under 22, it begins as autumn.

Crops in the growth and development period, not only require a certain temperature level (the temperature of the level), but also need a certain amount of heat, the sum of heat is usually expressed by the cumulative value of the daily temperature in the period, this cumulative value is called the accumulated temperature, the unit is the degree day, referred to as the degree.